Skip to main content

Will TRP help?

Member for

15 years 3 months
I wonder if anyone could comment... I've recently purchased the Royer SF12 at a decent second-hand price. I've only had the chance to try it out once on the application for which I bought it - for small ensenble choral recording. I really liked the tone and the imaging, even though the mic placement was not ideal (too close). However, the noise generated between mic and pre at 60db was to my ears an annoyance - not terribly loud, but still a nuisance. I was using Metric Halo ULN2 pres, which are very quiet and have plenty of gain, so I'm thinking that the SF12, while excellent for some applications, may not be ideal for this type of recording. For the life of me, I can't find anywhere on the net the specs on the SF12's self noise.

My questions are two: has anyone here had success using the AEA TRP with the SF12 on quiet applications like choral recording? I guess I'm wondering if the TRP will be a magic fix. I'm pretty sure it won't be curing a mic's own self-noise though - so it's probably a silly question.

Secondly - and this question is only asked because I don't know the noise specs of the SF12: would a pair of Coles 4040s be a quieter alternative?

Any comments would be welcome.

Dave

Comments

Member for

16 years 2 months

aracu Sun, 10/15/2006 - 11:53
By making it wider or narrower, you can adjust the angle
relative to the distance in front of the source, being determined
by the acoustics of the room and other factors. The 90 degrees
may be correct according to a rigid theory...but not ideal for every
situation. A slight adjustment is not going to automatically
produce a black hole.

Member for

21 years 2 months

Pro Audio Guest Sun, 10/15/2006 - 12:07
I am not talking about a "black hole"-- but you cannot escape the laws of physics. What good is picking up 20 degrees on the sides when it messes with the center balance? There is more to the equation than ideal accpetance angle-- look carefully at the polar plot.

I have never had a problem with acceptance angle with my SF12. Have you had such problems? IMO it would be better (and much easier) to pull the SF12 back a few feet.

Rich

Member for

16 years 10 months

DavidSpearritt Sun, 10/15/2006 - 13:42
Rich is spot on. The 90 degrees of Blumlein is essential to keep the linear distribution of phantom source location across the stereo image between the loudspeakers. If its less or more than 90 degrees then there will be compression or stretching distortion of source position, which is quite undesirable.

The correct localisation of sound sources with Blumlein is its number one characteristic, if you don't want that, then a pair of omnis or cardioids is a better bet.

Member for

16 years 10 months

DavidSpearritt Sun, 10/15/2006 - 14:45
If the 426 is picking up too much room sound when you have the image width correct, (must be a awash with reverb!), and you cannot move back without upsetting the direct to reverb ratio, then you need to use another technique other than Blumlein with 8's. Our 426 gets set to MS under these circumstances, cardioid M.

Member for

15 years 3 months

Duckman Sun, 10/15/2006 - 17:38
Just a slightly tangendental question... when using MS technique on a choir, is it important to have the sound source confined within the range of the Mid microphone, or can some elements of the choir be singing directly into the Side microphone, off axis to the Mid. I'm thinking in terms of a micing a choir in a fairly confined space, kind of, but not quite, in a semi-circle around an MS setup. Would that work in theory?

Member for

15 years 3 months

Duckman Sun, 10/15/2006 - 17:48
PS Dave and Rich, have you found that the TRP has added anything to your ribbon sound not already present with the top-notch preamps you already use?

Also, how do you plan on using the TRP on location conveniently... is it rack-mountable... or is there any special casing you use to carry around portable equipment like the TRP?

Member for

21 years 2 months

Pro Audio Guest Sun, 10/15/2006 - 17:57
So far I think the TRP gives the SF12 a little more body and focus. It is subtle but definitely there. I did not think my pres were lacking until the TRP.

As for travel-- I am sure it will stand alone because of ribbon inductance tendencies. Get the TRP too near significant AC and it picks it up. Ergo the separate PS.

Rich

Member for

20 years 9 months

FifthCircle Sun, 10/15/2006 - 21:32
Sonarerec wrote: By definition a ribbon mic is fig-8, so I really can't imagine any benefit to adjusting the bodies (in the case of two SF1s) to be wider than 90 degrees. Then you'd have a hole in the middle of the front image.

Rich

I've been doing this for years with my 426. There have been situations where I like a given position and either pattern manipulation or angle manipulation makes the recording work perfectly. I will never go wider than 90 degrees, but I have gone as narrow as 75 degrees- usually for closer mic'd chamber music.

I'm of the opinion that I don't care if it is "correct" acording to the book. If it sounds good, it is good, and I break the "rules" to make my recordings work.

That being said, there is a mic with an angle adjustment. I'm blanking on the exact one, but it is either the B&O stereo ribbon or the Speiden stereo ribbon. I'm pretty sure it is the B&O, but I'm not 100% sure.

--Ben

Member for

16 years 10 months

DavidSpearritt Mon, 10/16/2006 - 04:35
Duckman wrote: Just a slightly tangendental question... when using MS technique on a choir, is it important to have the sound source confined within the range of the Mid microphone, or can some elements of the choir be singing directly into the Side microphone, off axis to the Mid. I'm thinking in terms of a micing a choir in a fairly confined space, kind of, but not quite, in a semi-circle around an MS setup. Would that work in theory?

MS can take a very wide distributed source without the limitations of view angle, as there is no out of phase quadrants or regions to avoid, as there is in Blumlein. There is a spreadsheet somewhere or a Java beanlet or something that shows the patterns after matrixing, you can satisfy yourself of the coverage. It works in practice as well. :)

Member for

16 years 10 months

DavidSpearritt Mon, 10/16/2006 - 04:39
Duckman wrote: PS Dave and Rich, have you found that the TRP has added anything to your ribbon sound not already present with the top-notch preamps you already use?

Also, how do you plan on using the TRP on location conveniently... is it rack-mountable... or is there any special casing you use to carry around portable equipment like the TRP?

I still haven't yet used the Coles or TRP in a decent space with a decent source yet. In a couple of days, I have a wonderful baritone to record in our best theatre, am going to use the Coles and the AEATRP. Will post something if possible.

I have a Pelican case setup with the Coles and the AEATRP in it, along with the Coles Blumlein mount. It is self contained and will largely not be mixed up with other gear, ie phantom powered stuff.

Member for

21 years 2 months

Pro Audio Guest Mon, 10/16/2006 - 11:54
DavidSpearritt wrote: [quote=Duckman]when using MS technique on a choir, is it important to have the sound source confined within the range of the Mid microphone, or can some elements of the choir be singing directly into the Side microphone, off axis to the Mid.

MS can take a very wide distributed source without the limitations of view angle, as there is no out of phase quadrants or regions to avoid, as there is in Blumlein.
Well, it depends on what you consider is a MS pickup. We can certainly agree that the S is always a fig-8 mic. As for the M, certain people will limit it to being a cardioid. I say it can be anything you want from omni to fig-8, and even to shotgun mic as promoted by Sennheiser when they introduced MKH series.

If you use a fig-8 as M, the resulting LR will be equivalent to Blumlein (as long as the MS ratio is 1:1). If you want a MS pickup without any reversed polarity (or out of phase) quadrants, the M should be omni.

- Kewl

Member for

16 years 10 months

DavidSpearritt Mon, 10/16/2006 - 13:54
Yes, Kewl, you are correct of course, I should have been clearer.

The question arose about wide sound stages in choral recording, where you would assume that all the singers are "in front" of the array. I tend to define MS as a cardioid M, and with "normal" relative gains of M and S, there are negligable out of phase sections in front of the mic, where the singers are, even out wide the coverage is in phase.

I think this was the answer to the question.

Member for

16 years 11 months

mdemeyer Mon, 10/16/2006 - 20:31
I find the very natural pickup to the sides from the Fig 8 in MS is excellent in a wide choral setup. It also does very well on room ambiance, applause (for concert recordings - I hate bad sounding applause) and in situations where you have to deal with processionals, etc. in a concert.

Last month I recorded Chanticleer in a quite nice church using MS with a Schoeps MK21 (wide card) for M and the MK8 as the S mic. (Mic visible in upper-left corner of photo.)

(Dead Link Removed)

It is quite lovely... the slightly warm MK21 really shines (IMHO) as a choral mic and this configuration handled the fairly wide setup very well. I'll see if I can post a sample.

Michael

Member for

16 years 10 months

Simmosonic Mon, 10/16/2006 - 23:43
Duckman wrote: Does that mean that an SF12/24 or an R88 might not work so well in such a situation?

The SF12, SF24 and R88 are all Blumlein pairs...

If you use a Blumlein pair in MS (i.e. one bidirectional facing forward, one facing to the side), you'll still have the same out-of-phase quadrants to the left and right sides (90 degrees and 270 degrees off-axis) when it is decoded from MS to LR. No difference there between MS Blumlein and normal Blumlein.

So, if you're wanting to use MS Blumlein on a choir you will have no problems so long as you treat it like ordinary Blumlein and keep all the voices within the front quadrant (i.e. +/-45 degrees off-axis). You could also divide the voices up, of course, and have some coming into the rear quadrant with no problems. Just keep out of the side quadrants; leave them for room sound.

The main advantage of MS Blumlein, in my opinion, is for smaller ensembles where you want a good strong centre image. With normal Blumlein, a sound in the centre is captured by two capsules, and the quality depends very much on the matching of those capsules. With MS Blumlein, a sound in the centre is captured by one capsule only and is, therefore, potentially better.

With a large choir, I see no benefit in using MS Blumlein over normal Blumlein, especially with mics like the SF12 and SF24 where the two ribbons are very closely matched. I assume the R88 is the same, but I've only had limited time with that one.

For a small choir, where you can comfortably fit the entire ensemble inside the front 90 degree 'window', there may be a sonic benefit in going MS. But if in doubt, with the mics in questions, stick with standard Blumlein...

Member for

16 years 11 months

mdemeyer Sun, 10/22/2006 - 16:42
Sorry, haven't managed to get permission to post a sample from the Chanticleer performance, but here is a sample using an MK4/MK8 MS setup of the Taipei Philharmonic Chamber Choir recorded while they were touring in the US in July.

(Dead Link Removed)

Comments and suggestions always welcome.

I'll try to post the MK21/MK8 sample when I can...

Michael

Tags

x